Singulation is a process of separating a semiconductor die from other semiconductor dies on a wafer either completely by cutting through the wafer or by creating a trench in the wafer such that the dies can be separated relatively easily. Typically, singulation is performed after devices, such as complementary metal-oxide-semiconductor (“CMOS”) devices, are formed on the wafer.
The process of cutting into or completely through the semiconductor wafer between each die, however, can cause cracking in the surrounding semiconductor substrate. The cracking can also propagate into the devices formed on the wafer surface, causing the loss wafer die.
FIG. 1 illustrates a cross-section of a wafer that has had a prior art singulation process performed on it. In FIG. 1, trenches 101 have been scribed into the wafer to separate the dies 125 after the devices 115 have been formed on the dies. The dies have then been separated by a saw cut 110. In the prior art example of FIG. 1, however, either the trenches or the saw cut can cause cracking in the wafer substrate, which can effect electrical characteristics of the devices formed on the wafer prior to the trenches or saw cut or propagate to the devices themselves.